The present invention relates to an air distribution assembly for a rotary cutting apparatus having a shaft and a mantle, the mantle having at least one cutting member.
The invention also relates to a rotary cutting apparatus provided with such an air distribution assembly.
Air distribution in a rotary cutting apparatus is previously known and is performed by radial bores formed in the circumferential surface of a solid rotary cutter. Axial bores connect the radial bores with sources of vacuum and/or atmospheric pressure or over-pressure. Drilling of such axial and radial bores is time consuming and expensive, in particular since they have to be made with high accuracy.
U.S. Pat. No. 4,770,078 discloses in a discussion of the prior art (FIGS. 1-3) a one piece rotary cutter, which has to be removed from the frame when maintenance is needed. In order to allow the machine to be used during maintenance, a further rotary cutter including its static shaft must always be accessible.
In order to overcome that problem, U.S. Pat. No. 4,770,078 suggests to divide the rotary cutter into a rotatable shaft and a mantle. The mantle is connected to the rotatable shaft by means of pneumatic pressure. A drawback with this kind of rotary cutter is that it is difficult to index the rotary cutter relative to the anvil. Another drawback is the lack of support of the rotary cutter on the side opposite to the driven side.